Noisy Mixer

[andykala]

Hey there,
ok, so I have an old big-ass D&R 4000 series mixer (a.k.a. Dog&Rumble) which I have a soft spot for, although it probably needs to be put to rest soon. Anyway, a couple of years back after an electrical short, it blew a few circuits. Most were repaired, but there are a still a few minor glitches which generally dont affect my work.

The problem I have at the moment is quite a bit of noise out of my mixer. The weird thing is, that it is eliminated when I press most PFL buttons. When i pushed the PFLs (stereo) for an effects rack return, it still made the noise. so i unplugged it. Noise still there, but PFLs for these channels now eliminate noise also. There is only 1 channel which still has noise after pressing PFL (even with nothing plugged into that channel).

Do you guys think it's worth opening her up and unplugging that channel strip? If the noise is still there, would it indicate a problem in the main output bus?

Thanks in advance for any input!

ak.

[andykala]

Okkk looks like I'm removing a channel strip tonite!

[andykala]

Ok here's and update: a loose connection and noisy button was causing the noise on the particular channel strip, BUT the original issue remains. That is, hissing exists with all channels muted (or unmuted) but when ANY PFL is pressed, noise is eliminated.

Any help plz?

[Snatchman]

Very uncharacterlike with noise isues ( IME) with D & R consoles. Normally these are very quite consoles..!..I'm no techy but have you checked your PSU..?

[andykala]

Hi there Snatchman! Thanks for the reply!
To be honest I haven't checked my psu...i had it looked at last time the console crapped itself a couple of years back.
If it was the psu though, wouldn't you expected noise to persist when the pfl's were pressed?
Hmmm I'm just thinking, could the noise be a summation of minimal noise from each channel? I'll try to PFL all tracks tonight and see if the hiss is still there...